1. Field of the Invention
The present invention relates to an improvement in a cutter knife having a blade which is provided in the upper surface thereof with a plurality of weakening lines at which the blade can be cut so that, when the foremost blade section becomes dull, it can be cut off for putting the next blade section into use.
2. Description of the Prior Art
When a blade of a conventional cutter knife is replaced by a new one, a clip at the rear end portion of a sheath type holder is removed and a control knob is then slidingly moved to the rear end of the holder. Thus, a stopper for the control knob is removed therewith from the holder so that the blade is ready to be taken out.
When the blade is mounted in the holder, the former is inserted in the latter and the stopper is then fitted in a hole provided in the base portion of the blade. Then, the control knob is forwardly moved and the clip is attached to the rear portion of the holder so that the blade is fixed in the holder.
Thus, the removing and mounting of a blade of a conventional cutter knife is very troublesome.